X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fspi%2Fspi_bitbang.c;h=f1db395dd88981ca4bf7f2e8777c8e9f2c6cceee;hb=d41a5b7da223f7a80844fb3e948e8d5e6181f214;hp=0f7f5c64391cbb62700189d6c2cc89220811421e;hpb=ccf77cc4af5b048e20cfd9327fcc286cb69c34cc;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c index 0f7f5c6..f1db395 100644 --- a/drivers/spi/spi_bitbang.c +++ b/drivers/spi/spi_bitbang.c @@ -16,7 +16,6 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -#include #include #include #include @@ -167,9 +166,11 @@ int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t) /* nsecs = (clock period)/2 */ if (!hz) hz = spi->max_speed_hz; - cs->nsecs = (1000000000/2) / hz; - if (cs->nsecs > MAX_UDELAY_MS * 1000) - return -EINVAL; + if (hz) { + cs->nsecs = (1000000000/2) / hz; + if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000)) + return -EINVAL; + } return 0; } @@ -183,42 +184,27 @@ int spi_bitbang_setup(struct spi_device *spi) struct spi_bitbang_cs *cs = spi->controller_state; struct spi_bitbang *bitbang; int retval; - - if (!spi->max_speed_hz) - return -EINVAL; + unsigned long flags; bitbang = spi_master_get_devdata(spi->master); - /* REVISIT: some systems will want to support devices using lsb-first - * bit encodings on the wire. In pure software that would be trivial, - * just bitbang_txrx_le_cphaX() routines shifting the other way, and - * some hardware controllers also have this support. - */ - if ((spi->mode & SPI_LSB_FIRST) != 0) - return -EINVAL; - if (!cs) { - cs = kzalloc(sizeof *cs, SLAB_KERNEL); + cs = kzalloc(sizeof *cs, GFP_KERNEL); if (!cs) return -ENOMEM; spi->controller_state = cs; } - if (!spi->bits_per_word) - spi->bits_per_word = 8; - /* per-word shift register access, in hardware or bitbanging */ cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)]; if (!cs->txrx_word) return -EINVAL; - retval = spi_bitbang_setup_transfer(spi, NULL); + retval = bitbang->setup_transfer(spi, NULL); if (retval < 0) return retval; - dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n", - __FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA), - spi->bits_per_word, 2 * cs->nsecs); + dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs); /* NOTE we _need_ to call chipselect() early, ideally with adapter * setup, unless the hardware defaults cooperate to avoid confusion @@ -226,12 +212,12 @@ int spi_bitbang_setup(struct spi_device *spi) */ /* deselect chip (low or high) */ - spin_lock(&bitbang->lock); + spin_lock_irqsave(&bitbang->lock, flags); if (!bitbang->busy) { bitbang->chipselect(spi, BITBANG_CS_INACTIVE); ndelay(cs->nsecs); } - spin_unlock(&bitbang->lock); + spin_unlock_irqrestore(&bitbang->lock, flags); return 0; } @@ -240,7 +226,7 @@ EXPORT_SYMBOL_GPL(spi_bitbang_setup); /** * spi_bitbang_cleanup - default cleanup for per-word I/O loops */ -void spi_bitbang_cleanup(const struct spi_device *spi) +void spi_bitbang_cleanup(struct spi_device *spi) { kfree(spi->controller_state); } @@ -267,10 +253,16 @@ static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t) * Drivers can provide word-at-a-time i/o primitives, or provide * transfer-at-a-time ones to leverage dma or fifo hardware. */ -static void bitbang_work(void *_bitbang) +static void bitbang_work(struct work_struct *work) { - struct spi_bitbang *bitbang = _bitbang; + struct spi_bitbang *bitbang = + container_of(work, struct spi_bitbang, work); unsigned long flags; + int do_setup = -1; + int (*setup_transfer)(struct spi_device *, + struct spi_transfer *); + + setup_transfer = bitbang->setup_transfer; spin_lock_irqsave(&bitbang->lock, flags); bitbang->busy = 1; @@ -282,8 +274,6 @@ static void bitbang_work(void *_bitbang) unsigned tmp; unsigned cs_change; int status; - int (*setup_transfer)(struct spi_device *, - struct spi_transfer *); m = container_of(bitbang->queue.next, struct spi_message, queue); @@ -300,23 +290,19 @@ static void bitbang_work(void *_bitbang) tmp = 0; cs_change = 1; status = 0; - setup_transfer = NULL; list_for_each_entry (t, &m->transfers, transfer_list) { - if (bitbang->shutdown) { - status = -ESHUTDOWN; - break; - } - /* override or restore speed and wordsize */ - if (t->speed_hz || t->bits_per_word) { - setup_transfer = bitbang->setup_transfer; + /* override speed or wordsize? */ + if (t->speed_hz || t->bits_per_word) + do_setup = 1; + + /* init (-1) or override (1) transfer params */ + if (do_setup != 0) { if (!setup_transfer) { status = -ENOPROTOOPT; break; } - } - if (setup_transfer) { status = setup_transfer(spi, t); if (status < 0) break; @@ -350,12 +336,14 @@ static void bitbang_work(void *_bitbang) t->rx_dma = t->tx_dma = 0; status = bitbang->txrx_bufs(spi, t); } + if (status > 0) + m->actual_length += status; if (status != t->len) { - if (status > 0) - status = -EMSGSIZE; + /* always report some kind of error */ + if (status >= 0) + status = -EREMOTEIO; break; } - m->actual_length += status; status = 0; /* protocol tweaks before next transfer */ @@ -378,9 +366,10 @@ static void bitbang_work(void *_bitbang) m->status = status; m->complete(m->context); - /* restore speed and wordsize */ - if (setup_transfer) + /* restore speed and wordsize if it was overridden */ + if (do_setup == 1) setup_transfer(spi, NULL); + do_setup = 0; /* normally deactivate chipselect ... unless no error and * cs_change has hinted that the next message will probably @@ -405,20 +394,23 @@ int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m) { struct spi_bitbang *bitbang; unsigned long flags; + int status = 0; m->actual_length = 0; m->status = -EINPROGRESS; bitbang = spi_master_get_devdata(spi->master); - if (bitbang->shutdown) - return -ESHUTDOWN; spin_lock_irqsave(&bitbang->lock, flags); - list_add_tail(&m->queue, &bitbang->queue); - queue_work(bitbang->workqueue, &bitbang->work); + if (!spi->max_speed_hz) + status = -ENETDOWN; + else { + list_add_tail(&m->queue, &bitbang->queue); + queue_work(bitbang->workqueue, &bitbang->work); + } spin_unlock_irqrestore(&bitbang->lock, flags); - return 0; + return status; } EXPORT_SYMBOL_GPL(spi_bitbang_transfer); @@ -438,9 +430,10 @@ EXPORT_SYMBOL_GPL(spi_bitbang_transfer); * hardware that basically exposes a shift register) or per-spi_transfer * (which takes better advantage of hardware like fifos or DMA engines). * - * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup and - * spi_bitbang_cleanup to handle those spi master methods. Those methods are - * the defaults if the bitbang->txrx_bufs routine isn't initialized. + * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup, + * spi_bitbang_cleanup and spi_bitbang_setup_transfer to handle those spi + * master methods. Those methods are the defaults if the bitbang->txrx_bufs + * routine isn't initialized. * * This routine registers the spi_master, which will process requests in a * dedicated task, keeping IRQs unblocked most of the time. To stop @@ -453,10 +446,13 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) if (!bitbang->master || !bitbang->chipselect) return -EINVAL; - INIT_WORK(&bitbang->work, bitbang_work, bitbang); + INIT_WORK(&bitbang->work, bitbang_work); spin_lock_init(&bitbang->lock); INIT_LIST_HEAD(&bitbang->queue); + if (!bitbang->master->mode_bits) + bitbang->master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags; + if (!bitbang->master->transfer) bitbang->master->transfer = spi_bitbang_transfer; if (!bitbang->txrx_bufs) { @@ -475,7 +471,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) /* this task is the only thing to touch the SPI bits */ bitbang->busy = 0; bitbang->workqueue = create_singlethread_workqueue( - bitbang->master->cdev.dev->bus_id); + dev_name(bitbang->master->dev.parent)); if (bitbang->workqueue == NULL) { status = -EBUSY; goto err1; @@ -502,28 +498,12 @@ EXPORT_SYMBOL_GPL(spi_bitbang_start); */ int spi_bitbang_stop(struct spi_bitbang *bitbang) { - unsigned limit = 500; - - spin_lock_irq(&bitbang->lock); - bitbang->shutdown = 0; - while (!list_empty(&bitbang->queue) && limit--) { - spin_unlock_irq(&bitbang->lock); + spi_unregister_master(bitbang->master); - dev_dbg(bitbang->master->cdev.dev, "wait for queue\n"); - msleep(10); - - spin_lock_irq(&bitbang->lock); - } - spin_unlock_irq(&bitbang->lock); - if (!list_empty(&bitbang->queue)) { - dev_err(bitbang->master->cdev.dev, "queue didn't empty\n"); - return -EBUSY; - } + WARN_ON(!list_empty(&bitbang->queue)); destroy_workqueue(bitbang->workqueue); - spi_unregister_master(bitbang->master); - return 0; } EXPORT_SYMBOL_GPL(spi_bitbang_stop);